检索结果-南通市图书馆

parallelism and Optimization of Numerical Ocean Forecasting Model

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Ocean University of China 2016年第5期15卷 783-788页

作者： XU Jianliang PANG Renbo TENG Junhua LIANG Hongtao YANG Dandan College of Information Science and Engineering Ocean University of China Department of Computer and Network National Marine Environmental Forecasting Center Division of Information system National Marine Environmental Forecasting Center

According to the characteristics of Chinese marginal seas, the Marginal Sea Model of China(MSMC) has been developed independently in China. Because the model requires long simulation time, as a routine forecasting model, the parallelism of MSMC becomes necessary to be introduced to improve the performance of it. However, some methods used in MSMC, such as Successive Over Relaxation(SOR) algorithm, are not suitable for parallelism. In this paper, methods are developedto solve the parallel problem of the SOR algorithm following the steps as below. First, based on a 3D computing grid system, an automatic data partition method is implemented to dynamically divide the computing grid according to computing resources. Next, based on the characteristics of the numerical forecasting model, a parallel method is designed to solve the parallel problem of the SOR algorithm. Lastly, a communication optimization method is provided to avoid the cost of communication. In the communication optimization method, the non-blocking communication of Message Passing Interface(MPI) is used to implement the parallelism of MSMC with complex physical equations, and the process of communication is overlapped with the computations for improving the performance of parallel MSMC. The experiments show that the parallel MSMC runs 97.2 times faster than the serial MSMC, and root mean square error between the parallel MSMC and the serial MSMC is less than 0.01 for a 30-day simulation(172800 time steps), which meets the requirements of timeliness and accuracy for numerical ocean forecasting products.

关键词： parallelism partition steps faster serial dynamically forecasting marginal overlapped neighbor

Fast reaction of AlNPs promoted by oxide shell

在线全文

学校读者我要写书评

暂无评论

Fast reaction of AlNPs promoted by oxide shell

Adaptive design of an X-ray magnetic circular dichroism spectroscopy experiment with Gaussian process modelling

中国力学大会（CCTAM2019）

作者： Bao Wu FengChao Wu YinBo Zhu AnMin He Pei Wang HengAn Wu CAS Key Laboratory of Mechanical Behavior and Design of Materials Department of Modern Mechanics CAS Center for Excellence in Complex System Mechanics University of Science and Technology of China Laboratory of computational Physics Institute of Applied Physics and Computational Mathematics

Combustion of Aluminum nanoparticles(AlNPs) has long been investigated experimentally because of its use in various energetic formulations for propellants and explosives. But the limited spatio-temporal resolution in experiments in particular makes it challenging to explore the microstructural evolution of AlNPs oxidation and associated mechanisms. Here we perform large-scale reactive molecular dynamics simulations to study the structural evolution of AlNPs with 2-4 nm thick oxide shell in oxygen environment. We find the temporal hollowing processes of AlNPs for both symmetrical and asymmetrical oxidations, in which the morphological evolution can be understood by discrepant electric field and temperature distributions for different system. In the early time, core Aluminum atoms experience a fast reaction with oxide shell. Environmental oxygen does not react with AlNPs until the surface O/Al ratio decreases to ～1.2. Moreover, based on our simulation results, previous experimental data agree well with the proposed model, which can well describe the relationship between combustion efficiency and oxide shell thickness, reveling that oxide shell promotes other than hinders combustion of AlNPs. The molecular insights obtained here would be significant for understanding the underlying mechanism and further modelling of AlNPs combustion

关键词：

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

npj computational Materials 2018年第1期4卷 639-646页

作者： Tetsuro Ueno Hideitsu Hino Ai Hashimoto Yasuo Takeichi Masahiro Sawada Kanta Ono Quantum Beam Science research Directorate National Institutes for Quantum and Radiological Science and Technology1-1-1 KotoSayoHyogo 679-5148Japan Institute of Materials Structure Science High Energy Accelerator Research Organization1-1 OhoTsukubaIbaraki 305-0801Japan Elements Strategy Initiative center for Magnetic Materials Research Center for Magnetic and Spintronic MaterialsNational Institute for Materials Science1-2-1 SengenTsukubaIbaraki 305-0047Japan Department of Computer Science University of Tsukuba1-1-1 TennodaiTsukubaIbaraki 305-8573Japan Hiroshima Synchrotron Radiation center Hiroshima University2-313 KagamiyamaHigashihiroshimaHiroshima 739-0046Japan center for Materials research by Information Integration(CMI2) Research and Services Division of Materials Data and Integrated System(MaDIS)National Institute for Materials Science(NIMS)1-2-1 SengenTsukubaIbaraki 305-0047Japan

Spectroscopy is a widely used experimental technique,and enhancing its efficiency can have a strong impact on materials *** propose an adaptive design for spectroscopy experiments that uses a machine learning technique to improve *** examined X-ray magnetic circular dichroism(XMCD)spectroscopy for the applicability of a machine learning technique to *** XMCD spectrum was predicted by Gaussian process modelling with learning of an experimental spectrum using a limited number of observed data *** sampling of data points with maximum variance of the predicted spectrum successfully reduced the total data points for the evaluation of magnetic moments while providing the required *** present method reduces the time and cost for XMCD spectroscopy and has potential applicability to various spectroscopies.

关键词： spectroscopy circular spectroscopy

Parameter sensitivity study of the biogeochemical model in the China coastal seas

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Oceanologica Sinica 2015年第12期34卷 51-60页

作者： JI Xuanliang LIU Guimei GAO Shan WANG Hui National Marine Environmental Forecasting center Key Laboratory of research on Marine Hazards Forecasting National Marine Environmental Forecasting Center

In order to develop a coupled basin scale model of ocean circulation and biogeochemical cycling,we present a biogeochemical model including 12 components to study the ecosystem in the China coastal seas（CCS）.The formulation of phytoplankton mortality and zooplankton growth are modified according to biological characteristics of *** four sensitivity biological parameters,zooplankton assimilation efficiency rate（ZooAE_N）,zooplankton basal metabolism rate（ZooBM）,maximum specific growth rate of zooplankton（μ_（20）） and maximum chlorophyll to carbon ratio（Chl2C_m） are obtained in sensitivity experiments for the phytoplankton,and experiments about the parameter μ_（20＇）,half-saturation for phytoplankton NO_3 uptake（K_（NO_3）） and remineralization rate of small detritusN（SDeRRN） are *** results demonstrate that the biogeochemical model is quite sensitive to the zooplankton grazing parameter when it ranges from 0.1 to 1.2 d^（-1）.The K_（NO_3） and SDeRRN also play an important role in determining the nitrogen cycle within certain *** sensitive interval of KNO_3 is from 0.1 to 1.5（mmol/m^3）^（-1）,and interval of SEdRRN is from 0.01 and 0.1 d^（-1）.The observational data from September 1998 to July 2000 obtained at SEATS station are used to validate the performance of biological model after parameters *** results show that the modified model has a good capacity to reveal the biological process features,and the sensitivity analysis can save computational resources greatly during the model simulation.

关键词： China coastal seas biogeochemical model parameter sensitivity

Agent-based Simulation systems for Emergency Management

在线全文

学校读者我要写书评

暂无评论

International Journal of Automation and computing 2016年第2期13卷 89-98页

作者： Zhi-Chao Song Yuan-Zheng Ge Hong Duan Xiao-Gang Qiu College of Information system and Management National University of Defense Technology Hunan 410073 China Aeronautical University of China People Liberation Airforce Jilin 130012 China

Emergencies, which are very difficult to be forecasted, would always bring about huge harm to people. Therefore, to find ways to reduce such devastating effects, researches on emergency management have turned to be paramount. Nowadays, the rapid development of computer technology has supplied a new and effective idea for the researches of emergency management, namely that the researches can be done in computers by performing simulation experiments according to the artificial societies, computational experiments, parallel execution （ACP） approach. Guided by this approach, this paper has proposed one agent-based prototype simulation system to research emergency management. Firstly, structure of the simulation system oriented to emergency management was analyzed and designed. Then a simulation system oriented to public health emergency management was constructed to study the transmission of infectious diseases. Finally, several experiments were carried out based on the system, with several significant conclusions having also been obtained.

关键词： Agent-based simulation emergency management artificial societies computational experiments parallel execution (ACP) simulation system public health transmission of infectious diseases.

Construction and Implementation of the Online Data Analysis system on EAST

在线全文

学校读者我要写书评

暂无评论

Plasma Science and technology 2014年第5期16卷 521-526页

作者：杨飞肖炳甲张睿瑞 Institute of Plasma Physics Chinese Academy of Sciences Department of Computer Science Anhui Medical University center of Hefei Physical Science and technology University of Science and Technology of China

In order to obtain diagnostic data with physical meaning,the acquired raw data must be processed through a series of physical formulas or processing *** diagnostic data are acquired and processed by the diagnostic systems *** data processing programs are specific and usually run manually,and the processed results of the analytical data are stored in their local disk,which is unshared and ***,it is necessary to integrate all the specific process programs and build an automatic and unified data analysis system with shareable data *** paper introduces the design and implementation of the online analysis *** on the MDSplus event mechanism,this system deploys synchronous operations for different processing *** to the computational complexity and real-time requirements,combined with the programmability of parallel algorithms and hardware costs,the OpenMP parallel processing technology is applied to the EAST analysis system,and significantly enhances the processing efficiency.

关键词： EAST MDSplus OpenMP event data processing

Active learning for the power factor prediction in diamond-like thermoelectric materials

在线全文

学校读者我要写书评

暂无评论

npj computational Materials 2020年第1期6卷 254-260页

作者： Sheng Yasong Wu Jiong Yang Wencong Lu Pierre Villars Wenqing Zhang Materials Genome Institute Shanghai University200444 ShanghaiChina Qianweichang College Shanghai University200444 ShanghaiChina Department of Chemistry College of ScienceShanghai University200444 ShanghaiChina Material Phases Data system CH-6354 VitznauSwitzerland Department of Physics and Shenzhen Institute for Quantum Science&technology Southern University of Science and Technology518055 ShenzhenGuangdongChina Guangdong Provincial Key Lab for computational Science and Material Design and Shenzhen Municipal Key Lab for Advanced Quantum Material and DeviceSouthern University of Science and Technology518055 ShenzhenGuangdongChina

The Materials Genome Initiative requires the crossing of material calculations,machine learning,and experiments to accelerate the material development *** recent years,data-based methods have been applied to the thermoelectric field,mostly on the transport *** this work,we combined data-driven machine learning and first-principles automated calculations into an active learning loop,in order to predict the p-type power factors(PFs)of diamond-like pnictides and *** active learning loop contains two procedures(1)based on a high-throughput theoretical database,machine learning methods are employed to select potential candidates and(2)computational verification is applied to these candidates about their transport *** verification data will be added into the database to improve the extrapolation abilities of the machine learning *** strategies of selecting candidates have been tested,finally the Gradient Boosting Regression model of Query by Committee strategy has the highest extrapolation accuracy(the Pearson R=0.95 on untrained systems).Based on the prediction from the machine learning models,binary pnictides,vacancy,and small atom-containing chalcogenides are predicted to have large *** bonding analysis reveals that the alterations of anionic bonding networks due to small atoms are beneficial to the PFs in these compounds.

关键词： learning bonding prediction

Fully-Decoupled and Second-Order Time-Accurate Scheme for the Cahn–Hilliard Ohta–Kawaski Phase-Field Model of Diblock Copolymer Melt Confined in Hele–Shaw Cell

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Communications in Mathematics and Statistics 2024年第3期12卷 479-504页

作者： Junying Cao Jun Zhang Xiaofeng Yang School of Data Science and Information Engineering Guizhou Minzu UniversityGuiyang 550025People’s Republic of China Guizhou Key Laboratory of Big Data Statistics Analysis Computational Mathematics Research CenterGuizhou University of Finance and EconomicsGuiyang 550025People’s Republic of China Department of Mathematics University of South CarolinaColumbiaSCUSA

In this work,we consider numerical approximations of the phase-field model of diblock copolymer melt confined in Hele–Shaw cell,which is a very complicated coupled nonlinear system consisting of the Darcy equations and the Cahn–Hilliard type equations with the Ohta–Kawaski *** the combination of a novel explicit-Invariant Energy Quadratization approach and the projection method,we develop the first full decoupling,energy stable,and second-order time-accurate numerical *** introduction of two auxiliary variables and the design of two auxiliary ODEs play a vital role in obtaining the full decoupling structure while maintaining energy *** scheme is also linear and unconditional energy stable,and the practical implementation efficiency is also very high because it only needs to solve a few elliptic equations with constant coefficients at each time *** strictly prove that the scheme satisfies the unconditional energy stability and give a detailed implementation *** experiments further verify the convergence rate,energy stability,and effectiveness of the developed algorithm.

关键词： Phase-field Explicit-IEQ Darcy Decoupled Energy Stability Diblock copolymer melt

Theoretical Investigation on Internal Leakage and Its Effect on the Efficiency of Fluid Switcher-Energy Recovery Device for Reverse Osmosis Desalting Plant

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2013年第11期21卷 1216-1223页

作者：乞炳蔚王越王照成张燕平徐世昌王世昌 Chemical Engineering research center School of Chemical Engineering and Technology Tianjin Key Laboratoryof Membrane Science and Desalination Technology Tianjin University Tianjin 300072 China

This work is focused on the theoretical investigation of internal leakage of a newly developed pi lotscale fluid switcherenergy recovery device （FSERD） for reverse osmosis （RO） system. For the purpose of in creasing FSERD efficiency and reducing the operating cost of RO, it is required to control the internal leakage in a low level. In this work, the internal leakage rates at different leakage gaps and retentate brine pressures are investigated by computational fluid dynamics （CFD） method and validating experiments. It is found that the internal leak age has a linear relationship with the retentate brine pressure and a polynomial relationship with the scale of leakage gap. The results of the present work imply that low internal leakage and high retentate brine pressure bring benefits to achieve high FSRD efficiency.

关键词： internal leakage rate fluid switcher-energy recovery device computational fluid dynamics energytransfer efficiency